Latch mechanism



MW 37 BY WWW BE] 5 Juiy 22 1924. LSQZAWS J. LEDW INKA LATCH MECHANI SMFiled Aug. 27, 192] 2 Sheets-Sheet 1 1 N V EN TOR.

JbSE'PH LEONA/K14 Juiy 22, 1924. magma J. LEDWINKA LATCH MECJHANISMFiled Aug. 27. 1921 2 Sheets-Sheet 2 JOSEPH LEDW/NKA WW W By ATTORNEY.

Patented duly 22, 1924.

w hheld JOSEPH LIEDWINKA, 0F PHEADELPHIA, PENNSYLVANIA, ASSIG-NGE T0 G.BUDD MANUFACTURING COMPANY, OE PHELADHJPHIUL, PENNSYLVANIA, A COR-PORATION OF PENNSYLVAEIA,

LATCH MECHANISM Application filed August 27, 1921. serial No. 598,0 52.

anism which will require the application of only a very slight pressureor force, to the door in closing it, in order to retract the latch bolt.

Another object of my invention is to provide an improved latchconstruction in which friction between the relatively moving parts isvery largely reduced or eliminated.

Another object of my invention is to provide an improved latchconstruction in which the latch bolt will be securely retained inlooking position by engagemnt with the keeper, without the necessity foremploying comparatively stiff or strong springs for that purpose.

Another object ofmy invention is to provide an improved latchconstruction in which a swinging latch bolt is withdrawn from lookingposition by the actuation of a slidable bolt-operating member.

Further objects, and objects relating to details and economies ofconstruction and operation, will definitely appear from the detaileddescription to follow. Myinvention is clearly defined and pointed out inthe appended claims. A structure constituting a referred embodiment ofmy invention is illustrated in the accompanying drawin s, forming a partof this spec1ficat1on,in wh c Figure 1 is .a plan view of a latchemybodying my invention.

Fig. 2 is auview'of vation. I

Fig. 3 is a transverse, sectional view through the latch, taken on theline the latch in side ele-' of Fig. 1, and showing the operatingspindle and handles.

Fig. 4 is a sectional view on the line 4-4 of Fig; 3, showing the partsfor ac-. tuating the cit-operating member.

Fig. 5 is a sectional view taken on line 5-5 of Fig. 1, and i Fig. 6 isa perspective view of the boltoperating member.

In the drawings, the same reference numeral refers to the same partthroughout the several views, and the sectional views are taken lookingin the direction of the arrows at the ends of the section lines.

It is among the special purposes of my invention to provide a latch beltwhich is pivotally mounted to swing into and out of looking position,and which is so arranged that when in locking position the lockingstrain of the keeper is taken by the pivot stud of the latch bolt in adirection radially towards the axis of the saidstud, thereby relievingthe operating devices for the latch bolt from such strains. Toaccomplish this result in one form ot-embodiment of my invention.

the end surface of the swinging latch bolt is curved to an arcconcentric with the pivotal axis ofthe latch bolt and this curvedsurface is enga ed by the keeper when the latch bolt is in cokingposition. Normally,

in accordance with my invention, the latch bolt isyieldin ly maintainedinposition for its forward side surface to engage the keeper By imposingthe strain of the looking I engagement of the latch bolt and keeper,when the door is'in closed-position, upon the pivot of the latch bolt, Iam enabled to eliminate and avoid the use of stiff or strong springs fortaking. such strains, while at the same time securely retaining .thelock in its lockin position.

- It is also among t e special purposes of my invention to provideoperating means for the latch bolt, which, while permitting the yieldingswinging movement of the latch bolt, above referred to, during theclosing movement of the door, may be operated by suitable handles,easily and readily, and

i with the expenditure of only small force,

toefl'ect a manual withdrawal of thelatch bolt from locking positionwhen it isdesired to open the door. To accomplishthis result, inaccordance with my invention, I propose to employ means suitablyconnected to the swinging latch bolt, and which are mounted to sliderectilinearly in a direction tangential to the arc of swing of the latchbolt, and I propose to reduce to a minimum the area of surface contactof the sliding parts in order to reduce the friction of such slidingmovement.

I also provide a simple arrangement of manually operable means to.effect the withdrawal of the latch bolt, from its locking position,whenever desired, to effect the opening of the door. To this end Ipropose to employ a roll-back member arranged to engage the latchbolt-operating connections, and'yieldingly held in. its normal positionin which it permits the latch to be maintained in its locking position.

These various objects and purposes may be accomplished in many diflerentwa s, and, while I have shown and will-now scribe an illustrative simpleand eificient flange 11 and a swingingl embodiment of my invention, Iwish it to be understood that in the broadest scope of my invention, asdefined in the claims, I

do not desire to .be limited or restricted to thebase plate 10 nearthefiange 11 and provided with a pair of ears15 carrying a pivot in 16on which the latch bolt 17 is 'pivota 1y mounted. The latch bolt 17, if

desired, may be formed into a recess 25 .epening through its rear face,so that it'is substantially hollow and "is thereby correspondinglyreduced in weight. The 1 end surface 18 of the latch bolt is curved toan arc concentric with the axis of the pivot 16, and the front side ofthe latch bolt lies arallel to a radial plane through said axis.bolt-operating member 19 is provided for actuating the swinging latchbolt. This bolt-operating member is mounted so as to slide relative tothe base plate and it has an extended portion 24 which is pivotallyconnected to the latch bolt, as bythe pin 26. The body ortion of themember 19 has an elongate central opening 20, and, at, the end oppositethe extension 24, a ijde lug 21 which works in a slot 22 ormed in thebase. plate 10. The portion of thel'bolt-operating'member 19 adjacent Ithe lug 21, and the corresponding end of the central opening 20, isthicker than the body portion of said member 19, and is provided withthe-projecting portions 23 on the face thereof which is presented towardthe base plate-10, said projecting portions forming shoulders 40. Aspring 27 mounted on a post 42 carried by the base plate enga es the endof the member 19, adjacent the ug 21, and normally exerts its tension tourge the said member toward the flange 11, so asto swing the latch bolt17 forwardly on its'pivot into projected positionas clearly shown inFigs. 1, 2-and 3.

A bridge 30 mounted on the base plate 10 extends over the bolt-operatingmemvided to manually retract the bolt. For

this purpose I have shown a roll-back 3.8

which is journaled in the base plate at 29, and in the bridge, 30, at31. The rollback, 38, in the illustrative form shown,

has laterally-extending fingers 39 which her 19. Any suitable means maybe proroll-back to restore it to normal osition after it has beendisplaced there rom in retractin thebolt. The roll-back is provided witha square opening or passage 35 through which exten s the s uare spindle34, to which the operating andles 36 and 37 are attached. This is one ofthe customary expedients for actuating a rollback and it is obvious thatother means may be utilized for that purpose. When this latchconstruction is used in all-metal doors,

having two spaced panels between whichv the latch is inserted, I providea support,

32 for one of the escutcheon plates, which is secured to the bridge '30at 33, and has a central opening through which the spindle 34 extends.The latch mechanism cooperates with the usual keeper (not shown). Whenthe door, carryin this latch mechanism, is swung to close position, theedge of the keeper engages the front side or edge of the swinging latchbolt 17. The resist- 27, the friction between the latch bolt and itspivot, which friction is very small, and the friction between thebolt-operating member 19 and the bridge 30, and base plate 10 at thepoints where said member is guided by such parts. This latter frlctionis reduced because the area of the parts in surface contact is greatlyreduced, the only portion of the bolt-operating. member having suchsliding contact being the thicker portion adjacent the lug 21. 7Furthermore, it will be observed that the pressure aplied in closingthe'door when ,the front ace of the latch bolt engages the keeper,

is translated into a force actin in the direction of the length of thebjo t operating member and hence there is no tendency, as in theordinary sliding-bolt construction, to press the bolt-operating membertoward one of the parts on which it slides, which otherwise wouldincrease the sliding fric-- tion. When the door in closing has movedsufficiently far to permit the edge of the keeper to pass the outer endof the latch bolt 17, and to receive the are surface of the latchboltthereagainst, the spring 27 acting on the bolt-operating member 19swings the latch bolt forwardly to and maintains the same in its normallocking position with the keeper in engagement with the end surface 18of the latch bolt. When in this position, a force exerted on the door inthe direction to open it is applied to the end of the latch bolt in adirection radial of its pivot, the resultingstrain is taken by the latchbolt pivot and is not imposed upon the bolt-operating member 19.Consequently, a very light spring is all that is needed to maintain thebolt-operating member 19 in locking position. When it is desired toretract the latch, the operating spindle 34 is turned in eitherdirection by one or the other of the handles 36, 37. This causes one orthe other of the fingers 39 of the roll-back to press against a shoulder40 on the bolt-operating member 19, and slides said member back againstthe tension of spring 27, thereby retracting the latch bolt through theopening 13 out of en aging relation with the keeper 'on the 0017 jamb.The spring 28, acting on the flat back of the roll-back, restores it tonormal position when the handle is replaced and the spring 97 pressesthe bolt-operating member 19 to its normal position to again project thelatch bolt through the opening 13 and into the projected position shownin the drawings.-

By reducing the friction as described and by providing a construction inwhich only a light spring is needed to project the bolt, I have attainedobjects of my invention and produced a latch which is remarkablysensitive, that is to say, a very sli ht force applied to the door willbe su cient to latch-it.

What I claim as new and useful and of my own invention, and desire tosecure by Letters Patent is:

1. A latch mechanism comprising a base plate, a swingin latch boltmounted thereon, a bolt-operatlng member slidably mounted on said baseplate and provided with a lug sliding in a slot therein, the bodyportion of sand member being spaced from the base plate, said memberbein connected to said latch bolt, a rotatable ro l-back engaging saidbolt-operating member to actuate It)heksame, and means for rotating saidroll- 2. A latch mechanism comprising a base plate a swinging latch boltmounted thereon, a bolt-operating member connected to said latch boltandhaving its body portion spaced from said base plate but guided forsliding movement thereby, a roll-back positioned between said base plateand the body portion of said bolt-operating member and engaging saidmember to actuate the same, and means for. operating said roll-back.

3. A latch mechanism comprising a base plate, a swinging latch boltmounted thereon, a bolt-operatin member connected to said latch bolt andliaving its body ortion spaced from said base late but gui ed forsliding movement thereby, the body portion of said'member being providedwith a central opening, a roll-back extending through said centralopening and having portions working between the body'portion of saidbolt-operating member and the base plate and engaging saidbolt-operating member to actuate the same, and means for operating saidroll-back;

4. A latch mechanism comprising a base plate, a swinging latch boltmountedthereon, a bolt-operating member connected to: said latch boltand having its body ortion spaced from said base plate but gui ed forsliding movement thereby, the body portion of said member bein providedwith a central opening and pro ecting shoulders on each side thereof, aroll-back extending through said central opening and having portionsworking between the bod portion of said bolt-operating member an thebase plate and engaging said projecting shoulders to actuate thebolt-operating member,v and meaiis for operating said roll-back.

5. A latch mechanism comprising a base plate, a swinging latch boltmounted thereon, a bolt-operating member connected to said latch boltand having its body ortion spaced from said base plate but gui ed foring through said central opening. and having portions working betweenthe body portion of said bolt-operating member and the base plate, andengaging -said' projecting,

shoulders to actuate the bolt-operating member, and means for operatingsaid roll-book.

6. A latch mechanism comprising a base plate, a swinging latch boltmounted thereon, a bolt-operating member connected to said latch boltand having its body portion spaced from said base late but guided forsliding movement there ,y, the body portion of said member beingprovided with a central opening, projecting shoulders on each sidethereof, and a lug sliding in a slot pro- Vided in said base plate, aroll-back extend ing through said central opening and having laterallyextending fingers working between the body portion of saidbolt-operating member and the base plate and engaging said projectingshoulders to actuate the bolt-operating member, and means for operatingI said roll-back.

7. A latch mechanismcomprisin a base plate, a latch bolt pivotallymounte on said ase plate, a bolt-operating member mounted on said baseplate to slide in a right line and pivotally connected to said latchbolt, a roll-back engaging said bolt-operating member to actuate it inone direction, a spring engaging said bolt-operating member to actuateit in the opposite direction, a spring engaging said roll-back torestore it to normal positlon, and means for operating said roll-back.

8. A latch mechanism comprising a base plate, a swinging latch boltpivotally mounted on said base plate, a bridge mounted on said baseplate, a bolt-operating member connected to said latch bolt and slidablebetween said bridge and base plate, a rollback journaled in said bridgeand base plate and engaging said bolt-operating member to actuate it inone direction, and means for pivotally connected to said latch bolt anduided for sliding movement between said ridgp and base plate, saidbolt-operating mem er having a body portion spaced from said bridge andbase plate and a thicker portion having sliding contact therewith, andshoulders projecting from said thicker operatin portion toward the baseplate, a, roll-back ournaled in said bridge and base plate and havingfingers working between said boltoperating member and the base plate andengaging said shoulders to actuate the bolt pivotally connected to saidlatch bolt and uided for a sliding movement between said rid e and baselate, said bolt-operating member havin a ody portion s aced from saidbri'd e and base plate, a thic er portion having shding contacttherewith, and shoulders projecting from said thicker portion toward thebase plate, the body portion of said member being PIOVldGd'Wlth acentral opening, a roll-back extending through said central opening andjournaled in said bridge and base late, said roll-back having fingersworking etween said bolt-operating member and the base plateand enga ingsaid shoulders to actuate'the bolt-operating member in one direction,and means for operatingsaid roll-back.

11. A latch mechanism comprising a base plate, a swinging latch boltpivotally mounted on said base plate, a bridge mounted on said baseplate, a bolt-operating member connected to said latch bolt and slidablebetween said bridge and base plate, a rollback journaled in said bridgeand base plate and engagin said bolt-operating member to actuate it inone direction, an escutcheon support carried b said bridge, and meansfor operatin sai roll-back.

12. A late mechanism comprising a base plate, a latch bolt pivotedthereon, a bolt operatin member connected to said latch bolt an slidablymounted on said base plate, guide means on said member cooperating withthe base plate, said member being out of contact with said base plateexcept for-a limited area adjacent said guide means, and means foractuating said bolt operating member.

13. A latch mechanism comprising a base late provided with a slottherein, a latch olt pivoted on said base plate, a bolt operating memberpivotally connected to said latch bolt and having a lug sliding in saidslot, the body portion of said member being out of contact with saidbase plate except for a limited area adjacent said lug, and means foractuating said member.

14. A latch mechanism comprising a base plate having a slot therein, alatch bolt pivoted on said base plate, a sliding bolt member pivotallyconnected to said late bolt and having a lug working in said slot, saidmember being out of contact with said base plate except for a limitedarea adjacent said lug, a spring engaging said member adj acent said lugto project the latch bolt, and means for retracting said member againstthe pressure of said spring.

15. A latch mechanismcomprising a base plate, a latch bolt pivotedthereon, a bridge member fastened to said base plate,'a bolt operatingmember ivotally connected to said latch bolt and sliding between saidbrid e and base plate, guide means on said mem er cooperating with thebase plate,

said member being out of contact with said base plate and bridge exceptfor limited ture.

JOSEPH LEDWINKA.

